refactor: make Contract generic for Compiler and add metadata to CompilerOutput #845

Job	Run time
feature-checks	2m 29s
clippy	47s
doctest	55s
docs	34s
fmt	14s
test stable (ubuntu-latest)	1m 8s
test stable --all-features (ubuntu-latest)	2m 6s
test 1.70 (ubuntu-latest)	36s
test stable (macos-latest)	1m 15s
test stable --all-features (macos-latest)	2m 28s
test 1.70 (macos-latest)	46s
test stable (windows-latest)	2m 51s
test stable --all-features (windows-latest)	4m 17s
test 1.70 (windows-latest)	1m 22s
	21m 48s

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